The reasons for flight delays mainly due to weather, air traffic control, airlines, and passengers. Statistics show that bad weather accounts for over 70 percent of all delays. Air traffic control accounts for 15 percent, with airlines to blame for 10 percent and passengers causing 5 percent of all delays.

1. Weather

All stages of the flight including taking off, landing and flight in the air can be affected by inclement weather. Thunderstorms, low clouds, low visibility, low-altitude wind shear, atmospheric turbulence, air jet flow, turbulence, ice and other weather phenomena pose a direct threat to flight safety and influence the taking off and flight in the air, resulting in flight delay of places of departure and destination.

Thunderstorms are major reasons influencing flights in summer. Lightning and strong electric fields will disturb short wave radio, or even interrupt communication. Heavy rain, poor visibility, sharp wind changes and gusts have large effects on flight activities and ground equipment. Heavy rain, turbulence, ice, thunder, hail and squalls make it difficult to fly and aircraft may lose control, destroy, Horsepower reduction or even endanger flight safety.

Low clouds may affect landing. In case of landing when low clouds cover the airport, if the height to the ground is low and does not align with the R/W after clearing of all clouds, it may be too late to make a correction, resulting in going around again. It may also cause collision with ground obstacles and stalls with incorrect command and operation.

Low visibility has a considerable influence in the taking off and landing of aircraft. Rain, clouds, fog, sandstorms, dust, smoke and haze can reduce the visibility. Poor visibility of the ground may cause yaw and disorientation in flight and influence the safety of landing. If not handled correctly, it may endanger flight safety. When there is fog on the route, it affects the navigation. When there is fog in the target area, there are serious effects on the flight of visual landmarks, aerial shooting, photography, inspection and other activities.

Low-altitude wind shear is a serious threat to taking off and landing. Wind shear is a difference in wind speed or direction over a relatively short distance in the atmosphere. Strong wind shear can cause the aircraft to go around prematurely or forcibly. It may also cause aircraft stalls, losing control, or even air accident.

Atmospheric turbulence and air jet flow can cause aircraft turbulence. The aircraft may go up and down because of the irregular vertical movement of the air. Severe turbulence will increase the load of the wing and even break them, or bring the risk of aircraft descending or ascending several hundred meters.

Freezing is dangerous for flight. Since the accumulation of frost may increase the weight of the aircraft. Reasons such as the streamline of the wing changed, the weight of the propeller blade imbalance, sealing of the inlet pipe of the carburetor, difficulty in operation of landing gear, radio antenna out of action; reduce of horsepower or freezing of the throttle due to the reduce of air inflow may result in aircraft accident.

Explanation of common situations:

Q1: The weather of the destination airport is fine with clear visibility, why is the flight delayed because of the weather?

A: The fact that the weather at the destination airport is fine doesn’t mean it is suitable to land. Low clouds and area of thunderstorms covering the localizer of taking off and landing is the main cause.

Q2: The weather of the destination airport is fine with clear visibility and the flights of airport is normally operated, why is it delayed because of the weather?

A: The meteorological conditions on the flight path cannot be overflown, such as area of thunderstorms.

Q3: Why can some of the flights go, but some flights to the same place are told they cannot go because of the weather?

A: There are many reasons for this situation. Firstly, you must know that the standard of aircraft taking off and landing is related to their types. The flight standard of different companies with the same type of aircraft also has a difference. Decisions that aircraft commanders make according to the weather and trend are different too. Whether the aircraft can take off or not depends on the judgments that aircraft commanders make according to the condition of the aircraft, airport and weather. Civil aviation law prescribes that aircraft commanders can refuse flight if they consider the aircraft, airport, weather or other condition do not mean the requirements.

Q4: Why can’t we go yet since the snow has been stopped?

A: Though the snow has stopped, airlines should clear the snow on the airframe to ensure flight safety and prevent decrease of lift in the process of taking off. What’s more, in order to ensure that the friction coefficient of the runway meets the safety standard, the airport will also remove snow and ice on the runway and taxiway.

2. Air traffic control

The air route of civil aviation is in restricted airspace. In order to guarantee flight safety, the air traffic control department will control air traffic to prevent near-miss or mid-air collision in air routes or airports with high traffic flows.

Explanation of common situations:

Q1: All the passengers have boarded, the door has closed and other aircraft have taken off, why aren’t we?

A: It is in traffic control and the aircraft is waiting in line. The crew will explain to the passengers. Other craft can take off because their destination and orientation are different. They are not affected by this traffic control.

Q2: The aircraft is ready, but stopped after taxiing for a while, why hasn’t it taken off for a long time?

A: Because the runway is limited. There are many aircraft which will land or take off, and they are entering the runway at certain safe intervals. Some busy airports or at peak times, the air traffic is overloaded, the same as traffic on the ground at times. It is normal for an aircraft to taxi on the ground and wait for a long time.

Q3: Since there is traffic control, why don’t we board later or wait in the terminal?

A: The time of traffic control is not long, but flights in the same direction may be many. If your flight is ready, you can apply for takeoff to air traffic control earlier. The earlier you apply to takeoff the shorter the time you wait. If the time for waiting is long, it may be caused by other reasons. In this situation, aircraft are asked to be ready since the airspace may be open at any time. If the time for waiting is too long and there is no clear message when it will take off, the aircraft commander will arrange passengers wait in the terminal.

3. Airlines

Reasons for flight delay from airlines such as mechanical failure, flight time, and flight plan adjustment etc…

Explanation of common situations:

Q1: Does it violate the passengers’ rights that airlines cancel or merge flights due to flight delay?

A: Actually, cancelling or merging the flight is to protect the profit of the passengers. Airlines will cancel or merge flight plans to solve the problem that the front flight delay affects the next flight so as to recover the order.

Q2: Why is there consistent time delay?

A: This is where the most complaints are from passengers. Each airline has a dispatching center which masters the operation of all the aircraft. Once there is one flight delay, it affects all flights, the dispatching center will make adjustments so as to recover the flight and inform the following flights to prepare. The dispatching center will also estimate a time of delay. But there will be other changes, including new incidents. If delay occurs again, the plans also need change.

4. Passengers

Reasons for flight delay from passengers:

Passengers don’t board on time, leave from stopover station or call off after boarding. In order to ensure flight safety, the airlines must exercise strict clearance checks in the cabin. It is important to prevent consigning dangerous goods and leaving.

Passengers are slow to board. If the flight finishes boarding earlier, the crew can apply for taking off to air control department earlier. Then taking off can be much earlier.

Passengers due to flight delays and other factors such as occupation of the aircraft, or denied boarding occasional excesses, do so because of the flight delays caused by more serious cases of delay. Those passengers have infringed other passengers’ profits while protecting their own profits. These behaviors are illegal.

Passengers should set aside enough time to arrive at the airport to check in and pay attention to the boarding time on the boarding pass. Passengers should board as soon as possible after hearing the broadcast. If you need to change your itinerary, please contact the airline in time.

If a flight is delayed, airlines, the airport and security units of Civil Aviation Administration will provide corresponding services guarantee and recover the flights as soon as possible.

1. Information

Airlines will announce the information of the delay, cancel or recovery of the flight on the flight information screen, via official websites, official microblogs, television, radio and other media. What’s more, the information of flight adjustment will be sent to passengers by call centers and messaging platforms in real time. Hence, passengers are supposed to fill in their real mobile phone number when booking tickets so as to get the flight adjustment information in time. The airport will assist the airlines in announcing the information on the flight adjustment information when there are a large amount of flight delays.

2. Service and guarantee

Airlines will supplement ground service staff to assist the passengers in refunding or changing their tickets, explain to the passengers and calm them. The airlines will deploy the flights and make plans of complementary flights in time in order to resume normal operation in the shortest time.

The airport will make sure that lighting, ventilation and air conditioning facilities in the airport terminal are in good condition during the flight delay. The restaurants are in business. In order to ensure that the friction coefficient of the runway meets the safety standard, the airport will also remove ponding or snow and ice on the runway and taxiway in time when there is a rainstorm or snow.

3. Rights of passengers

Passengers can change or refund their tickets when their flight is delayed or cancelled. Different airlines have different rules. Please consult the airlines.

Airlines shall provide passengers with free meals or accommodation as compensation when flights are delayed or cancelled in places of departure because of the airlines. If it doesn’t result from the airlines, the airlines shall assist the passengers in arranging accommodation, but the expenses shall be paid by the passengers.

●Safeguard rights

1. Safeguard rights and interests legitimately and legally

Passengers shall safeguard their rights and interests legitimately and legally when flights are delayed. Some passengers, on strike, occupying the aircraft, destroying airport facilities, assaulting the staff and other aggressive behavior when flight delay, have violated “Regulations on Civil Aviation Security of the People’s Republic of China” and “Law of the People’s Republic of China on Penalties for Administration of Public Security”, the Public Security Department will take it seriously.

2. Dial-a-cheat confidential hotline

If passengers are unsatisfied with the service, they can complain to the airlines, airport or Civil Aviation Administration of China Consumer Affairs Center. Complainants can complain in written form, or e-mail or by telephone. They will need to supply their name and information as well as the facts and information about what they are complaining about.